1. Field of the Invention
This invention relates to a compound type of keyboard detector, and particularly to a detector device, whereby a given number of pins can be used for a relatively greater number of keys.
2. Description of the Prior Art
Most of the conventional keyboard detectors are one-dimensional type (i. e., a direct mapping type) (i.e., a direct mapping type) as shown in FIG. 1, or a two-dimensional type (i.e., a matrix type) as shown in FIG. 2 to be connected with a keyboard; if more keys are to be added, the number of pins of the IC has to be increased accordingly. In terms of an IC package, more pins will cause a higher package cost, i.e., the manufacturing cost thereof will be increased.